I run plants in a veg unit all the way through flower. I am actually running my 2nd set that way as we speak. Used clones, letting them veg for a couple weeks and then in flower they will go. First set did quite well, its almost like DWC without a bubbler + sprayers, plants really like it as water is almost always available to some part of the roots. I did rails in my initial aero setup and was not impressed, a while back using a SS vegger I thought about using them start to finish so I broke it down to single unit and works great!
I use a mix of growing methods, Flood & Drain, DWC and also the aero vegger. My consistently best grows.yields come from Flood & drain in 6x6x6 rockwool. but I like to play.